Inclined fitting with thread providing flat engagement with box wall



April 2, 1963 R. w. ASBURY 3,083,990 INCLINED FJITTING WITH THREAD PROVIDING FLAT ENGAGEMENT WITH BOX WALL Filed April 13, 1959 I8 42 \(D I 48 ATTORNEY 3,3833% Patented Apr. 2, 1963 3,033,990 HNELENED FHTTHNG WITH THREAD PRDVIDHNG FLAT ENGAGEMENT WiTH BOX WALL Ray W. Asbury, Galesbnrg, Ill. (97 SW. 6th Ave, Galva, llll.) Filed Apr. 13, 1959, Ser. No. 805,771 6 Claims. (Cl. 285-161) This invention relates to a fitting or connector for use in the connection of electrical conduit or the like to terminal, junction, outlet and like boxes and in the connection of similarly related parts peculiar to the electrical wiring field.

Those versed in the art are familiar with the standard practice of running a conduit along a wall or surface to lead into a terminal box, for example, mounted on the wall, and wherein the conduit-receiving opening in the box is outwardly offset from the plane of the wall or surface so that the box-proximate end of the conduit must be bent to provide a double bend or ogee curve to accommodate this offset. Although electrical workers are quite adept in the use of conduit benders for elfecting the double bend directly in the conduit, that practice is timeconsuming and there has been proposed heretofore a connector or adapter comprising a short length of tubing or the like pro-formed with the requisite double bend or ogee curve. This fitting or adapter has one end coaxially receivable of the conduit and its other end ofifset on an axis parallel to the first end for coaxial receipt by the offset opening in the box. Although such fittings have found some acceptance by the trade, they are relatively costly because of the manufacturing problems encountered in providing the double bend.

According to the present invention, a less expensive and superior connector or fitting is provided which features only a single bend in lieu of the double bend. Significant in this regard is the fact that, although the single bend results in an obtusely angled portion which enters the box opening at an angle, this portion is externally threaded in such manner that the threads are square with the plane of the box wall in which said opening is provided and thus this threaded portion is capable of receiving a standard lock not of the conventional type. Likewise, this threaded portion is receivable of any standard internally threaded electrical fitting, adapter, coupling, etc. The invention features further an external stop on the obtusely angled portion which is also square with the box wall so as to be cooperative in clamping relation with the nut. It is another object to provide an improved fitting or connector of two-piece construction in the zone of the stop and to construct the stop as means serving the additional function of interconnecting these pieces. Other objects relate to modified forms of connectors having varied means for coaxially receiving the terminal ends of conduits and equivalent components. The feature of the single gentle angle enables easier wire pulling and eliminates snagging of the fish line.

The foregoing and other important objects and features, inherent in and encompassed by the invention, will become apparent to those versed in the art as preferred embodiments of the invention are disclosed, by Way of example, in the ensuing description and accompanying sheet of drawings, the several figures of which are described below.

FIGURE 1 is a plan view of a representative conduitto-box connection employing one form of connector.

FIGURE 2 is a side view, partly in section, of the same.

FIGURE 3 is a longitudinal section of the fitting or connector per se of FIGURES l and 2.

FIGURE 4 is a longitudinal section of a modified fitting or connector.

FIGURE 5 is a longitudinal section of still another form of fitting or connector.

It should be noted at the outset that the disclosure is based largely upon representative structures and a typical installation and certain representative dimensions are given and terms employed in the interests of clarity and exposition. Hence, these are not to be regarded as restrictive. For example, a box 10 is shown as illustrative of a junction, terminal or outlet box or like component mounted on a surface 12 along which a length of conduit 14 is run for connection to the box. As will be clear, wires are subsequently run through the conduit for connection to an outlet, for example (not shown) carried by the box. The surface 12 may be a floor, wall, ceiling, joist etc., as will be clear to those skilled in the art. The conduit shown is of the standard half-inch type, but, as noted, size differences are not material.

The box 10 has a back 16 afiixable to the surface 12 as by screws 18 and further has a marginal wall structure including an end wall 20 perpendicular or normal to the back 16 as well as to the surface 12.. This wall has therein a circular opening 22 formed on an axis 24 ofiset outwardly from the back 16 and the disposition of this opening, as is customary, is such that part of its peripheral portion, as at 26, is also spaced outwardly from the back 16. Hence, the axis 24 is also parallel to but is offset outwardly from the axis 28 of the conduit 14, and, since the position of the opening 22 is as described, the conduit cannot run directly or coaxially into the opening and at the same time lie against or relatively close to the surface 12. As pointed out above, the offset has heretofore been accommodated by providing either a double bend or ogee curve directly in the conduit or by interposing between the terminal end of the conduit and the box wall 20 a preformed connector having the requisite double bond. As also stated above, the present invention constitutes an improvement over the double-bend fitting by employing a simpler and less costly fitting having a single bend.

One form of such fitting or connector is shown in FIGURES 1-3 and is indicated as a whole by the numeral 39. This connector comprises a tubular member, here of cylindrical section, having first and'second integral or rigidly related tubular portions 32-34 disposed in endto-end relation as to each other at a single obtuse angle A, here resulting from a single bend 36 in a one-piece length of tubing, for example, which bend forms, at the junction of the two portions, 3 crimp affording a radially inward displacement of metal that produces a conduit stop 38. The inside diameter of the portion 32 is such as to snugly and coaxially receive the terminal end of the conduit 14, which abuts the stop 38. In practical use, the stop may be used as an index from which length, position, etc. of conduit, boxes etc. may be measured, since fittings such as that at 30 are produced and sold in standard lengths and sizes according to conduit and box types and dimensions. As stated before, the present disclosure is based on standard half-inch conduit.

Because of the obtuse angle A between the portions 32 and 34 and since the axis of the portion 32 is coincident with the conduit axis 28, the portion 34 will slope outwardly from the portion 32 toward the box 10, lying on an axis 49 which will intersect the axis 24 of the box opening 22 substantially in the plane of the box wall 20. In the present case, and by way of illustration, the angle A is on the order of 165, and the axis 49 will of course intersect the plane of the wall 20 at an angle of Hence, the terminal end part 42 of the portion 34 will be non-coaxial with the opening 22, and the obtuse angle A will be duplicated between the axes 24 and 40. In conventional boxes, the opening at 22 is always oversize and thus readily accommodates entry of the terminal part 42 at the angle indicated.

In the fitting 30, the terminal end part 42 and the main body of the portion 34 are of two-piece construction and the two pieces are rigidly interconnected by means of a flange 44 on the part 42 and a rim 46 of rolled section on the portion 34. This structure, in addition to incorporating elements that interconnect the two pieces 32 and 34, functions as external stop means adapted to abut the outside of the box wall 20. Significant in this respect is the fact that the plane of the stop means, afforded by the rolled section -46, is perpendicular not to the axis 40 of the portion 34 but to the axis 24 of the opening 22, and is thus also perpendicular to the axis 28 as well as to the surface 12, Hence, the stop means is parallel to the box wall 20 and therefore flatly or squarely abuts the outside of this wall to cooperate with a nut 48 threaded onto the terminal part 42 which, as is clear, projects beyond the stop means 46' for entry into the box via the opemng 22.

The part 42 is externally threaded at 50, and attention is directed to the fact that the threads are based on or square with not the axis 40 but the axes 24 and 28 and with the planes of the surface 12, stop means 46 and box wall 20. That is to say, the threads are generated in such manner that they receive the nut 48-which may be an electricians standard half-inch lock nut employed with conventional fittings, and this nut, when threaded onto the threaded part 42, runs downhill along the axis 40 but its rear face is normal to the axis 28 and thus is parallel to and fiatly abuts the inner face of the box wall 20, being thereby parallel to the stop means 46 and cooperative with the stop means to effect the necessary clamping action for securing the fitting or connector 30 tightly in place. In the representative example shown, the relation of the threads 50 to the basic structure is such that one face of each 60-thread is at an angle of 3 0 to the plane of the stop means 46. This outstanding angled thread is the major factor enabling the use of the single-bend fitting 30 and, what is more, the usethereof with conventional associated parts, thereby materially reducing costs both in manufacture and in installation on the job. The terminal end part 42 may be threaded either before or after it is joined to the portion 34 by the means 46.

The nature of the thread 50 may be best understood by noting that a standard thread of comparable lead and pitch is formed on a right cylinder; i.e., a cylinder whose axis is perpendicular to its base. The thread 50 is formed instead on an oblique cylinder but has a lead and pitch substantially the same as a standard thread, in which regard it must be recognized that, in the field of conduits and fitting, precision is not a virtue and tolerances are quite generous. In forming the thread 50, a preferred practice involves modification of a standard /2" threading die by removal from the back side thereof of a sufficient number of teeth to provide what may be regarded as an enlarged counterbore coaxial with the two or three remaining rows or convolutions of teeth at the front or starting side of the die. The die is rotated about its axis and the fitting is fed to the front or starting side of the die along a feed axis intersecting the die axis at an angle of (angle A is 165) substantially in the plane of the front teeth of the die. In other words, the feed axis is comparable to the axis 40.

As the fitting end advances into the die at a feed rate based on the aforesaid lead and pitch, successive convolutions are formed about what may be regarded as the oblique cylinder; i.e., the cylinder having as its base a plane perpendicular to the die axis and having the feed axis (axis 40) as its principal axis. Thus approximately each convolution of the thread 50 is offset radially as well as axially from the preceding convolution and the counterbore at the back side of the die accommodates this ofiset. In effect, the axis of each convolution may be generally regarded as offset radially from that of the preceding convolution if it be supposed that the feeding of the fitting to the die is incremental rather than continuous and this offset will always be in the same radial direction (downwardly or toward the axis 28 and to the left in FIG. 2). Since the industry will accept and even prefers a Glass 1 fit (Marks, Mechanical Engineers Handbook, Revised 5th edition, p. 861), the standard lock nut having approximately 1 /2 convolutions is readily threadable on the thread 50. Actually the thread fits acceptably into other components to the extent of three or more convolutions and if both internal and external tolerances are on the high side a complete fit will be obtained.

A modified form of fitting is shown at 30 in FIGURE 4 in which the basic difference over the fitting 30 of FIGURES 1-3 is that the fitting 30' has a counterbore 38' in lieu of the bend-produced stop 38 for limiting entry of the terminal end of the conduit 14. Other than this, the fitting 30 may be identical to the fitting 30, having portions 32', 34', stop means 46' and a terminal end part '42 threaded at 50.

In FIGURE 5, a fitting or connector 30", identical to the fitting 30 as to basic features 32", 34", 46", 42 and 5%", differs by provision of a threaded end on the first or conduit-proximate portion 32", which further employs an external annular shoulder 38", at the junction of the angle between the two portions, for cooperation, for example, with a connector or coupling suggested at 14". In the case of the threaded portion 32", threading is done on the basis of the axis of the portion 32", or, standard threads are provided.

The foregoing examples will readily suggest others in the exploitation of the basic features of the invention residing in the single bend connector or fitting having the angled threading adapted to receive a standard lock nut, and, those versed in the art, on the basis of this disclosure and current knowledge will readily produce equivalent designs, all without departure from the spirit and scope of the invention.

What is claimed is:

1. An electrical conduit or like fitting for use with a terminal or like box having a back adapted to rest on a fiat surface and a wall perpendicular to said back and having an opening therethrough offset outwardly from and on an axis parallel to said back, comprising a tubular member having a first portion with a straight axis parallel to the surface and a portion of the periphery of which is adapted to lie tangent to said surface for coaxial connection to the terminal end of a conduit or the like running along said surface, and a second portion joined to said first portion for entry into the box via said opening, said second portion being wholly straight and joined to said first portion at a single obtuse angle so that the axis of said second portion intersects the axis of the opening generally in the plane of said wall, and said second portion having external stop means thereon perpendicular to the axis of the first portion and thus adapted to lie fiat against the outer side of the box wall, and said second portion at the part thereof within the box and axially beyond the stop means being provided with an external thread having substantially the lead and pitch of a standard thread of the same type and size but having its suecessive thread convolutions generated respectively about axes substantially parallel to and substantially uniformly offset radially toward the axis of the first portion for receiving a standard internally threaded lock nut adapted thereby to lie flat against the inside of the box wall for cooperation with the stop means to clamp said fitting to the box.

2. The invention defined in claim 1, in which: said second portion is of two-piece construction including Separate coaxial pieces related end-to end in the plane of the stop means, and said stop means includes elements cooperative with said pieces to join the same together.

3. The invention defined in claim 1, in which: the first portion has a coaxial threaded terminal end part.

4. The invention defined in claim 1, in which: the first and second portions are of one-piece construction in the zone of the obtuse angle between them and said angle results from a single bend in the member, and a portion of the member at said bend is displaced radially inwardly to afford a stop ofiset axially inwardly of the terminal end of said first portion.

5. An electrical conduit or like fitting for use with a terminal or like box having a back adapted to rest on a fiat surface and a wall perpendicular to said back and having an opening therethrough otfset outwardly from and on an axis parallel to said back, comprising a tubular member having a first portion with a straight axis parallel to the surface and a portion of the periphery of which is adapted to lie tangent to said surface for coaxial connection to the terminal end of a conduit or the like running along said surface, and a second portion joined to said first portion for entry into the box via said opening, said second portion being wholly straight and joined to said first portion at a single obtuse angle so that the axis of said second portion intersects the axis of the opening generally in the plane of said wall, and said second portion at the part thereof within the box being pro- 2 vided with an external thread having substantially the lead and pitch of a standard thread of the same type and size but having its successive thread convolutions generated respectively about axes substantially parallel to and substantially uniformly offset radially toward the axis of the first portion for receiving a standard internally threaded lock but adapted thereby to lie fiat against the inside of the box wall.

6. An electrical conduit or like fitting 'for use with a terminal or like box having a back adapted to rest on a flat surface and a wall perpendicular to said back and having an opening therethrough ofiset outwardly from and on an axis parallel to said back, comprising a tubular member having a single bend therein to atford first and second wholly straight portions related to each other at a single obtuse angle and respectively having straight axes meeting at said angle, said first portion being adapted for coaxial connection to a conduit or the like running along said surface and said second portion being adapted to enter the box opening at an angle to the box Wall, and said second portion at its terminal end Within the box being provided with an external thread having substantially the lead and pitch of a standard thread of the same type and size but having its successive thread convolutions generated respectively about axes substantially paral lel to and substantially uniformly ofiset radially towards the axis of the first portion for receiving a standard internally threaded lock nut adapted thereby to lie fiat against the box wal.

References Cited in the file of this patent UNITED STATES PATENTS 572,911 Schmidt Dec. 8, 1896 916,931 McMurtioe Mar. 30, 1909 2,497,126 Langman Feb. 14, 1950 2,531,892 Reese Nov. 28, 1950 2,553,304 Smith May 15, 1951 OTHER REFERENCES 474,745 Great Britain Nov. 8, 1937 

1. AN ELECTRICAL CONDUIT OR LIKE FITTING FOR USE WITH A TERMINAL OR LIKE BOX HAVING A BACK ADAPTED TO REST ON A FLAT SURFACE AND A WALL PERPENDICULAR TO SAID BACK AND HAVING AN OPENING THERETHROUGH OFFSET OUTWARDLY FROM AND ON AN AXIS PARALLEL TO SAID BACK, COMPRISING A TUBULAR MEMBER HAVING A FIRST PORTION WITH A STRAIGHT AXIS PARALLEL TO THE SURFACE AND A PORTION OF THE PERIPHERY OF WHICH IS ADAPTED TO LIE TANGENT TO SAID SURFACE FOR COAXIAL CONNECTION TO THE TERMINAL END OF A CONDUIT OR THE LIKE RUNNING ALONG SAID SURFACE, AND A SECOND PORTION JOINED TO SAID FIRST PORTION FOR ENTRY INTO THE BOX VIA SAID OPENING, SAID SECOND PORTION BEING WHOLLY STRAIGHT AND JOINED TO SAID FIRST PORTION AT A SINGLE OBTUSE ANGLE SO THAT THE AXIS OF SAID SECOND PORTION INTERSECTS THE AXIS OF THE OPENING GENERALLY IN THE PLANE OF SAID WALL, AND SAID SECOND PORTION HAVING EXTERNAL STOP MEANS THEREON PERPENDICULAR 